Bone fixation plates are often positioned over a fractured or otherwise damaged portion of bone and secured thereto using bone screws inserted through screw holes of the bone fixation plate. The screw holes extend transversely through the bone plate and are sometimes formed with threads to lockingly engage a head of the bone screw. Variable angle screws may be employed which permit a user to insert the screw through the plate at a user-selected angle relative to an axis of the plate hole. However, available variable angle screw systems may produce burrs when the screw head is locked in the plate hole. The burrs mostly arise in systems larger than 3.5 mm and when the screw is angulated relative to the plate hole. In angulated positions, the sharp edges of the plate hole thread act as a die and generate burrs from the screw head thread. Damage to the bone plate or bone screw in this manner is undesirable.